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R. K. EVANS. GRIPPING DEVICEFOR CABLE 'WAYHS.

(No Model.)

No. 295,915. Patented Apr. 1, 1884.

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NI-TED STATES PATENT Fries.

RICHARD K. EVANS, OF WVASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO THE CABLE RAILWAY COMPANY, OF SAN FRANCISCO, CALIFORNIA.

GRIPPING DEVICE FOR CABLE-WAY S.

SPECIFICATION forming part of Letters Patent No. 295,915, dated April 1, 1884.

Application filed August 13, 1883. (No model.)

To all 1071 0712, itmay concern: Belt known that I, RICHARD K. EVANS, of

. the city of \Vashington, and District of Columbin, have invented certain Improvements in Grips for Endless-Cable ays; and I hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings, making partof this specification, in which- Figure 1 is a side view of a clamping-plate of the upper jaw of a grip. Fig. 2 is a perspective view of a shoe to go into one of the jaws of the grip. Fig. 3 is a verticalsectional view of the jaws of a' grip with the improved plate and shoe combined. Fig. dis a side view of a grip-jaw having channels in itslower face, and the shoe with corresponding ribs on its upper surface, the clam ping-plate being shown in dotted lines. Figs. 5 to 11, inclusive, show modifications of my improvement.

Inall gripping devices now constructed for endless cable ways, and especially those endless-cable ways adapted for propelling streetrailway cars, the shank of the grip is a broad and comparatively thinbar or series of bars of steel, moving edgewise through the slot in l the sunken tube in which the cable is located.

This construction produces great strength in the gripper in resisting edgewise strains, and as a consequence, when by any accident some obstacle suddenly arrests the travel of the gripthe gripper oi the cable when great and unexpected resistances are met by I the grippershank; and my invention consists in providing the gripper with a device which will, at a predetermined strain, automatically relieve the gripper of the cable, as will be hereinafter more specifically set forth,

In order that those. skilledin the art may make and use my invention, I will proceed to describe the manner in which I have carried it out.

i In the said drawings, Figs. 1, 2, and 3 illustrate the most economical form of my releasing device. The shank of the gripper a, which is usually made of steel, is provided with thesteel shoe-holder b, and at its lower extremity, on

the inner side, is provided a series of angular grooves, c, to receive correspondiugly-shaped ribs 0 on the cast-iron shoe d. Bolted to the side of the shoe-holderis the angular clamping-plate 6, provided with a series of angular grooves, c, to receive the correspondinglyshaped ribs t" t" on the cast-iron shoe d. The lower shoe, m, and its holder 71, are made after the same manner with the upper shoe and holder, with the exception that their sides'are vertical. The ribs and grooves are the same. The cast-iron shoes alone are in contact. under pressure, with the cable E. After. it is determined what amount of edgewise breakingstrain the shank of the gripper will bear safely, the ribs 011' the cast-iron shoe are made of a proper size to shear off immediately before such a strain is reached by the pull of the cable, and thereby allow the cast-iron shoe or shoes to strip out of the gripper and release its hold on the cable. As the size of the ribs 0 and c" on the cast-iron shoe need only be of such strengthas to safely bear the pull necessary to transport a loaded street-car, and, as the pulling-strain is very much less than the strain to endanger the breaking of the gripper, the ribs maybe made to shear off anywhere intermediate of these two limits of strain. The

shoes d should be cast in quantities, and be on hand ready to replace any that may be stripped from the holders, and those which are stripped can be removed at leisure from the tube where they fall, as they can in no way interrupt the travel of the cable.

Fig. aillustrates a modification of my inven-- tion wherein the ribs are cast on the top of the upper cast-iron shoe and on the bottom of thelowershoe,thegroovesbeinginthebottoms of the receivingsockets of the shoe-holders.

Figs. 5, 6, and 7 illustrate a modification wherein the clamping-plates and lower shoeholders are provided with rectangular extension-plates p p, which sustain the ends of the shoes, made with smooth surfaces, the said plates beidg made to sustain a predetermined breaking-strain, and in breaking they allow the shoes to strip from their holders and release the cable.

backs of the cast iron shoes fit over ribs t, projecting from a soft-metal section, P, cast into the shoe-holders. Thisis highly advantageous when it is desired to havelight breaking-strain relieve the gripper.

Figs. 10 to 14, inclusive, illustrateamodification of my invention wherein a bolt, is, having a predetermined resistance, passes through the ends of the sh0e-holders and sustains the shoe.

The size of the bolt may bevaried indefinitely without altering the bearings or holes in the shoe-holders by turning down the bolt between the interior faces of the two shoe-holders. In this form the ends of the shoes may 15' be rounded; but it is not necessary.

Having thus described my invention, whatI claim as new, and desire to secure by Letters Patent, is-

The comblnation of a grip for cable-ways, 20.

a removable shoe or shoes, and intermediate fastening devices adapted to rupture at apredetermined strain, substantially as described.

RICHD. K. EVANS.

Vitnesses:

T. WALTER FOWLER, JOHN L. CONDRON. 

